Los Angeles: Actress Anne Hathaway has revealed that she spent most of her time in a gym to prepare for her character in "The Dark Knight Rises".

The actress, who is one of the new faces on the cast list of Christopher Nolan's third "Batman" movie, plays Catwoman in it. She said that the director wanted her to be able to do her own stunts in the movie.

"I had to physically transform," a website quoted her as saying. This is the first superhero movie that Hathaway has been a part of. The actress is currently filming for director Tom Hooper's "Les Miserables"."The Dark Knight Rises" releases July 20.